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/*
* CDDL HEADER START
*
* The contents of this file are subject to the terms of the
* Common Development and Distribution License, Version 1.0 only
* (the "License"). You may not use this file except in compliance
* with the License.
*
* You can obtain a copy of the license at usr/src/OPENSOLARIS.LICENSE
* or http://www.opensolaris.org/os/licensing.
* See the License for the specific language governing permissions
* and limitations under the License.
*
* When distributing Covered Code, include this CDDL HEADER in each
* file and include the License file at usr/src/OPENSOLARIS.LICENSE.
* If applicable, add the following below this CDDL HEADER, with the
* fields enclosed by brackets "[]" replaced with your own identifying
* information: Portions Copyright [yyyy] [name of copyright owner]
*
* CDDL HEADER END
*/
/*
* Copyright 2005 Sun Microsystems, Inc. All rights reserved.
* Use is subject to license terms.
*/
#pragma ident "%Z%%M% %I% %E% SMI"
#include <sys/types.h>
#include <sys/errno.h>
#include <sys/proc.h>
#include <sys/procfs.h>
#include <sys/sysmacros.h>
#include <sys/uio.h>
#include <sys/cmn_err.h>
#if defined(__sparc)
#include <sys/stack.h>
#endif
#define STACK_BUF_SIZE 64 /* power of 2 */
int
prusrio(proc_t *p, enum uio_rw rw, struct uio *uiop, int old)
{
/* longlong-aligned short buffer */
longlong_t buffer[STACK_BUF_SIZE / sizeof (longlong_t)];
int error = 0;
void *bp;
int allocated;
ssize_t total = uiop->uio_resid;
uintptr_t addr;
size_t len;
/* for short reads/writes, use the on-stack buffer */
if (uiop->uio_resid <= STACK_BUF_SIZE) {
bp = buffer;
allocated = 0;
} else {
bp = kmem_alloc(PAGESIZE, KM_SLEEP);
allocated = 1;
}
#if defined(__sparc)
if (p == curproc)
(void) flush_user_windows_to_stack(NULL);
#endif
switch (rw) {
case UIO_READ:
while (uiop->uio_resid != 0) {
addr = uiop->uio_offset;
len = MIN(uiop->uio_resid,
PAGESIZE - (addr & PAGEOFFSET));
if ((error = uread(p, bp, len, addr)) != 0 ||
(error = uiomove(bp, len, UIO_READ, uiop)) != 0)
break;
}
/*
* ENXIO indicates that a page didn't exist. If the I/O was
* truncated, return success; otherwise convert the error into
* EIO. When obeying new /proc semantics, we don't return an
* error for a read that begins at an invalid address.
*/
if (error == ENXIO) {
if (total != uiop->uio_resid || !old)
error = 0;
else
error = EIO;
}
break;
case UIO_WRITE:
while (uiop->uio_resid != 0) {
addr = uiop->uio_offset;
len = MIN(uiop->uio_resid,
PAGESIZE - (addr & PAGEOFFSET));
if ((error = uiomove(bp, len, UIO_WRITE, uiop)) != 0)
break;
if ((error = uwrite(p, bp, len, addr)) != 0) {
uiop->uio_resid += len;
uiop->uio_loffset -= len;
break;
}
}
/*
* ENXIO indicates that a page didn't exist. If the I/O was
* truncated, return success; otherwise convert the error
* into EIO.
*/
if (error == ENXIO) {
if (total != uiop->uio_resid)
error = 0;
else
error = EIO;
}
break;
default:
panic("prusrio: rw=%d neither UIO_READ not UIO_WRITE", rw);
/*NOTREACHED*/
}
if (allocated)
kmem_free(bp, PAGESIZE);
return (error);
}
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